PM: Separate hibernation code from suspend code

[ With Johannes Berg <johannes@sipsolutions.net> ]

Separate the hibernation (aka suspend to disk code) from the other suspend
code.  In particular:

 * Remove the definitions related to hibernation from include/linux/pm.h
 * Introduce struct hibernation_ops and a new hibernate() function to hibernate
   the system, defined in include/linux/suspend.h
 * Separate suspend code in kernel/power/main.c from hibernation-related code
   in kernel/power/disk.c and kernel/power/user.c (with the help of
   hibernation_ops)
 * Switch ACPI (the only user of pm_ops.pm_disk_mode) to hibernation_ops

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Greg KH <greg@kroah.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@nigel.suspend2.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 25 insertions, 30 deletions

diff --git a/include/linux/pm.h b/include/linux/pm.h
index 6e8fa3049e5d..87545e0f0b58 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -107,26 +107,11 @@ typedef int __bitwise suspend_state_t;
 #define PM_SUSPEND_ON           ((__force suspend_state_t) 0)
 #define PM_SUSPEND_STANDBY      ((__force suspend_state_t) 1)
 #define PM_SUSPEND_MEM          ((__force suspend_state_t) 3)
-#define PM_SUSPEND_DISK         ((__force suspend_state_t) 4)
-#define PM_SUSPEND_MAX          ((__force suspend_state_t) 5)
-
-typedef int __bitwise suspend_disk_method_t;
-
-/* invalid must be 0 so struct pm_ops initialisers can leave it out */
-#define PM_DISK_INVALID         ((__force suspend_disk_method_t) 0)
-#define PM_DISK_PLATFORM        ((__force suspend_disk_method_t) 1)
-#define PM_DISK_SHUTDOWN        ((__force suspend_disk_method_t) 2)
-#define PM_DISK_REBOOT          ((__force suspend_disk_method_t) 3)
-#define PM_DISK_TEST            ((__force suspend_disk_method_t) 4)
-#define PM_DISK_TESTPROC        ((__force suspend_disk_method_t) 5)
-#define PM_DISK_MAX             ((__force suspend_disk_method_t) 6)
+#define PM_SUSPEND_MAX          ((__force suspend_state_t) 4)
 
 /**
  * struct pm_ops - Callbacks for managing platform dependent suspend states.
  * @valid: Callback to determine whether the given state can be entered.
- *      If %CONFIG_SOFTWARE_SUSPEND is set then %PM_SUSPEND_DISK is
- *      always valid and never passed to this call. If not assigned,
- *      no suspend states are valid.
  *      Valid states are advertised in /sys/power/state but can still
  *      be rejected by prepare or enter if the conditions aren't right.
  *      There is a %pm_valid_only_mem function available that can be assigned
@@ -140,24 +125,12 @@ typedef int __bitwise suspend_disk_method_t;
  *
  * @finish: Called when the system has left the given state and all devices
  *      are resumed. The return value is ignored.
- *
- * @pm_disk_mode: The generic code always allows one of the shutdown methods
- *      %PM_DISK_SHUTDOWN, %PM_DISK_REBOOT, %PM_DISK_TEST and
- *      %PM_DISK_TESTPROC. If this variable is set, the mode it is set
- *      to is allowed in addition to those modes and is also made default.
- *      When this mode is sent selected, the @prepare call will be called
- *      before suspending to disk (if present), the @enter call should be
- *      present and will be called after all state has been saved and the
- *      machine is ready to be powered off; the @finish callback is called
- *      after state has been restored. All these calls are called with
- *      %PM_SUSPEND_DISK as the state.
  */
 struct pm_ops {
         int (*valid)(suspend_state_t state);
         int (*prepare)(suspend_state_t state);
         int (*enter)(suspend_state_t state);
         int (*finish)(suspend_state_t state);
-        suspend_disk_method_t pm_disk_mode;
 };
 
 /**
@@ -276,8 +249,6 @@ extern void device_power_up(void);
 extern void device_resume(void);
 
 #ifdef CONFIG_PM
-extern suspend_disk_method_t pm_disk_mode;
-
 extern int device_suspend(pm_message_t state);
 extern int device_prepare_suspend(pm_message_t state);
 
diff --git a/include/linux/suspend.h b/include/linux/suspend.h
index 9d2aa1a12aa0..d74da9122b60 100644
--- a/include/linux/suspend.h
+++ b/include/linux/suspend.h
@@ -32,6 +32,24 @@ static inline int pm_prepare_console(void) { return 0; }
 static inline void pm_restore_console(void) {}
 #endif
 
+/**
+ * struct hibernation_ops - hibernation platform support
+ *
+ * The methods in this structure allow a platform to override the default
+ * mechanism of shutting down the machine during a hibernation transition.
+ *
+ * All three methods must be assigned.
+ *
+ * @prepare: prepare system for hibernation
+ * @enter: shut down system after state has been saved to disk
+ * @finish: finish/clean up after state has been reloaded
+ */
+struct hibernation_ops {
+        int (*prepare)(void);
+        int (*enter)(void);
+        void (*finish)(void);
+};
+
 #if defined(CONFIG_PM) && defined(CONFIG_SOFTWARE_SUSPEND)
 /* kernel/power/snapshot.c */
 extern void __init register_nosave_region(unsigned long, unsigned long);
@@ -39,11 +57,17 @@ extern int swsusp_page_is_forbidden(struct page *);
 extern void swsusp_set_page_free(struct page *);
 extern void swsusp_unset_page_free(struct page *);
 extern unsigned long get_safe_page(gfp_t gfp_mask);
+
+extern void hibernation_set_ops(struct hibernation_ops *ops);
+extern int hibernate(void);
 #else
 static inline void register_nosave_region(unsigned long b, unsigned long e) {}
 static inline int swsusp_page_is_forbidden(struct page *p) { return 0; }
 static inline void swsusp_set_page_free(struct page *p) {}
 static inline void swsusp_unset_page_free(struct page *p) {}
+
+static inline void hibernation_set_ops(struct hibernation_ops *ops) {}
+static inline int hibernate(void) { return -ENOSYS; }
 #endif /* defined(CONFIG_PM) && defined(CONFIG_SOFTWARE_SUSPEND) */
 
 void save_processor_state(void);